The present invention relates to methods and apparatus for lateral drilling. More specifically, but not by way of limitation, this invention relates to drilling substantially horizontal drain holes from substantially vertical oil and gas wells, coal degasification wells, geothermal wells, solution mining wells and the like.
Well known in oil fields are low production wells in deposits such as tight sandstones where the flow and collection of oil is greatly restricted by a combination of low oil flow within the sands and a limited area of exposure of the well to the producing zone as limited by the diameter of the wellbore and the depth of the producing zone.
Adding to the flow problem are oils of high viscosity which move slowly in most sands, shales, chalks, limestones, evaporites and the like.
Although many other methods for drilling lateral boreholes have been proposed and successfully demonstrated, this invention differs in scope and requirement, sine qua non.
The present invention provides simple and effective means to readily develop within existing wellbores, especially in marginal and shallow-well fields, a multiplicity of small diameter drain holes at any depth and direction within the pay zone, at any deviated angle up to the horizontal and beyond, and in many ground conditions for up to a few hundred feet each, although in some cases it may be for a few thousand feet.
This invention is viewed as being an improvement over prior art methods and apparatus for many of the conditions encountered in oil and gas fields. It is in this spirit that the present invention will find its useful place amongst the abundance of known methods and apparatus.